The objective is to build a single-piece Rubble Rescue Radar (RRR) system. The system will combine inventor's proven radar with data acquisition, processing hardware and Inventor's algorithms and software. The combined system must be able to measure, detect, process and indicate real-time results.
Inventor currently produces handheld pre-production prototype radars for Government applications. Multiple versions of prototype radars have been built and demonstrated that meet all of the requirements for a rubble penetrating device. Inventor has unique impulse technology based on intellectual property, an advanced development (diverse engineering skills) capability, and practical experience integrating UWB systems.
Inventor is developing MicroPower Radars (MPR) for commercial and government applications including weapons diagnostics, covert military applications and other defense mission support. Inventor engineers can shape impulses to fit almost any application.
Inventor's MPR Systems are a fundamentally different type of wireless device. Based on new Inventor intellectual property, know-how, and expertise, inventor's sensors emit much shorter pulses than most radars and randomizes the timing of these pulses. Inventor has also developed ultra-wideband antennas, which are matched to the radar signal and has experience in optimizing antennas for different applications. These design advantages are discussed further below. Finally, because the MPR systems are built out of a small number of common electronic components, they are compact and inexpensive to produce. General specifications of inventor's typical existing systems is outlined below:
Based on emitting and detecting very low amplitude and short voltage impulses, the MPR has a very sensitive window for accurately detecting reflections from boundaries between different materials. Many of these radar systems can also be considered “digital,” because they emit very fast edges of digital square waves and then upon receiving impulse signals, immediately convert back into digital signal. Sensors make up the majority of systems prototyped to date; however, communication devices have also been demonstrated.
Another approach in the design of RCLAD is to exploit signal-processing gain through spectral analysis for the detection of heartbeat and breathing. Note, that in the ROC curves presented above, multiple pulses can make a significant difference in detection. Spectral match filtering employs the entire radar return sequence (i.e. multiple arrivals or pulses). Detection in the spectral domain will therefore afford a processing gain of approximately 13 dB for a 20 second observation window, as the period of an heart beat is only about 1 sec. Should further investigation on the signal spectral analysis methods prove to be more successful, the radar pulse amplitude and antenna gain need not be increased significantly from inventor's present design.
As an example of signal processing, shown below is a simulation of the heart beat detection for multiple subjects with observation at 10 s and 5 s window length. As depicted by the spectral plots in FIG. 7, the two heartbeats are clear in the longer (top) observation window of 10 sec., but is lacking for the shorter observation window of 5 sec. (below).
Longer integration times (time-on-target) help to resolve individual targets. Inventor's radar will display prompt results that a target exists and the longer the radar remains on-target, the more resolution the radar will achieve. In addition, the confidence level of the estimate will increase with time on target. Results clearly indicate.
Inventor has developed a prototype that is able to discriminate between targets in order to permit casualty location. The handheld scanner shall provide a snapshot azimuth and range information for a minimum of forty yards open air, twenty feet through non-conducting obstructions such as rubble.
Inventor recently developed a flashlight-sized radar capable of detecting the heartbeat and breathing motion of human targets through foliage and light rubble. The extreme sensitivity to such small movements by such small targets comes at a price—platform stability. If the platform moves, the small target signal may be swamped by the signal generated by the platform motion. This analysis was designed to determine the tolerable platform motion. First the target signal will be evaluated then the platform motion signal (vs. amplitude and frequency) will be measured. From these, an estimate of motion tolerance may be derived.